Structural Analysis, Magnetocaloric Effect, and Critical Exponents for La0.6Sr0.2Na0.2MnO3 Manganite

Abstract

This work focuses on the structural, magnetocaloric effect, and critical exponent investigations of La0.6Sr0.2Na0.2MnO3 manganite prepared via sol–gel method. XRD analysis confirms the rhombohedral structure with $$ R\overline{3}c $$ symmetry for this sample, and Rietveld method was used to estimate its different structural parameters. The sample presents FM-PM phase transition of second-order type at TC = 309 K. The maximum of magnetic entropy change (− $$ \Delta {S}_M^{max} $$ ) and relative cooling power (RCP) reach values of about 3.57 J kg−1 K−1 and 214.46 J kg−1, respectively (at μ0H = 5 T). These values indicate that La0.6Sr0.2Na0.2MnO3 sample can be used as active magnetic refrigerator. Critical exponents (β, γ, and δ) of the sample have studied by analyzing the M(μ0H, T) isotherms using different techniques. The estimated values of these critical exponents are found to be different to those predicted for standard theoretical models.